Quote:
Originally Posted by BestRN
Hi,
K10D but as they were out of the kit lens, I got a used-but-in-excellent-shape 67mm Pentax 16-45 DA 1:4 (22) ED-AL wide angle lens. (have NO idea what most of those numbers mean :-)
|
67mm is the filter size. It's usually not actually used as part of the description of the lens.
16-45 is the focal length range (i.e. zoom range) in millimeters -- one would usually say 16-45mm.
"DA" is Pentax's designation for lenses designed for digital SLRs -- they don't necessarily fill a full film frame (so they can be smaller and lighter), they have designed-for-digital optical coatings, and (unrelated to digital but a feature of all DA lenses) they have a quick-shift features where you can tweak the autofocus manually without switching the body into MF mode.
1:4 is usually the way one specifies magnification, or how good it is at being a macro lens. 1:4 isn't that exciting -- so you know macro isn't really the point of the lens if you see that. (You want 1:2 or better.) But this lens is actually 1:3.8, so either that's just rounded, or more likely, it's a typo for:
f/4 -- this is a constant-aperture zoom, which means the widest aperture of f/4 is available over the entire focal length. The kit lens, by contrast, is "f/3.5 - f/5.6", which means it starts out a fraction of a stop faster at the very wide end, but in the middle is slower and at the telephoto end is much slower. This is a huge advantage of the lens you have -- it makes autofocusing faster, the viewfinder brighter, and allows a narrower depth of field if you want to use selective focus in your composition.
The (22) is the smallest (slowest) aperture the lens can use. 22 is pretty normal. (On a point & shoot camera, by contrast, f/8 is usually the minimum.)
ED means that at least one lens element uses extra-low dispersion glass, which reduces chromatic aberration, so your picture has fewer color artifacts and is sharper.
AL means that at least one lens element is aspherical -- this generally is a part of the design used to reduce distortion, and can replace multiple normal lens elements, making the overall lens smaller and lighter.
So now you know.
The upshot is: this is a much better lens than the kit lens.
Quote:
|
get the zoom for just a little addition of $$ on my part). I probably paid WAY too much for the used lens...but it really does take nice group shots and vistas. However, the zoom quickly became my
|
Hard to say. The lens is theoretically a little over $400 and then minus a $100 rebate, but it's often hard to find in stock at all. And if it's in good condition, a used lens of this quality will retain most of its original value.